Argument results in a positional CLI argument. Option results in a keyword CLI argument, preceded with a --.

Notice that "Camila" here is an optional CLI argument, not a CLI option, because we didn't use something like "--name Camila", we just passed "Camila" directly to the program. Typer also supports another older alternative syntax for declaring CLI arguments with additional metadata.

But I wanted --pinboard-token to be an option on the main command, not on the subcommands. It’s essentially required, so I need to check for it, and didn’t want to do that multiple times. I also want to not repeat myself in each command. ... import typer from types import SimpleNamespace cli = typer.Typer() @cli.callback() def main( ctx: typer.Context, pinboard_token: str = typer.Option(None, envvar="PINBOARD_TOKEN"), ): if not pinboard_token: print( "Missing pinboard token; pass --pinboard-token or set env[PINBOARD_TOKEN]" ) raise typer.Exit(1) ctx.obj = SimpleNamespace(pinboard_token = pinboard_token) @cli.command() def all(ctx: typer.Context): # do something with ctx.obj.pinboard_token @cli.command() def new(ctx: typer.Context): # do something with ctx.obj.pinboard_token if __name__ == "__main__": cli()

Arguments are determined by the order they are passed while options have a specific name attached and the other no longer matters. import typer from typing import List from pathlib import Path app = typer.Typer(name="demo", add_completion=False, ...

In Typer you can also define CLI option short names the same way you can customize the long names. You can pass positional arguments to typer.Option() to define the CLI option name(s).

To make a CLI option required, you can put typer.Option() inside of Annotated and leave the parameter without a default value.

August 11, 2025 - Arguments are simpler for required inputs. Options are better for optional or multiple inputs.

also I tried to make default value "all" instead of None but still not working. I always get this error: Option [flag name] requires an argument

February 14, 2023 - It's only possible to pass an exact number of space separated values via an option, but not a list: https://typer.tiangolo.com/tutorial/multiple-values/options-with-multiple-values/ Multiple values are only possible via argument, yet the documentation for the two types reads almost identical (at least the first few paragraphs): https://typer.tiangolo.com/tutorial/multiple-values/arguments-with-multiple-values/

In this example, the value received for the CLI argument name will be treated as str. The value for the CLI option --age will be converted to an int and --height-meters will be converted to a float. And as female is a bool CLI option, Typer will convert it to a "flag" --female and the counterpart --no-female.

But the use of Optional doesn't affect Typer in any way, e.g. it doesn't tell Typer if a value is required or not. ... // Check the help $ uv run python main.py --help // Notice the [default: Wade Wilson] ✨ Usage: main.py [OPTIONS] [name] Arguments: name [default: Wade Wilson] Options: --help ...

In Typer, there are two primary classes for providing CLI parameter configuration: Argument results in a positional CLI argument. Option results in a keyword CLI argument, preceded with a --.

August 10, 2020 - Is there a clean way in typer? https://stackoverflow.com/questions/40182157/shared-options-and-flags-between-commands I'd like to share options in subcommands. A workaround is using a callback on a common parent command.

def app( device: str = typer.Option( None, "--device", "-d", help="Select the device you want to proceed with apples, oranges, banana", callback=__device_callback is_eager=True, ), soc: Optional[str] = typer.Option( "EFR", "--soc", "-s", help="Select the soc for the device type apples.

Parameters to our command line interface may be both CLI Options and CLI Arguments: from typing import Annotated import typer app = typer.Typer() @app.command() def register( user: Annotated[str, typer.Argument()], age: Annotated[int, typer.Option(min=18)], score: Annotated[float, typer.Option(max=100)] = 0, ): print(f"User is {user}") print(f"--age is {age}") print(f"--score is {score}") if __name__ == "__main__": app() Argument( default=..., *, callback=None, metavar=None, expose_value=True, is_eager=False, envvar=None, shell_complete=None, autocompletion=None, default_factory=None, parser=N

November 15, 2021 - Typer is a command line interface (CLI) framework for python that utilizes the pydantic type framework. This framework has turned out to be…

June 15, 2022 - I already checked if it is not related to Typer but to Click. ... from typing import Optional, List import typer import os app = typer.Typer() @app.command() def start( debug: bool = typer.Option(False), output_dir: str = typer.Option(os.getcwd()), flows: Optional[List[str]] = typer.Option(None, "--flow", "-f")): typer.echo(f"Debug mode: {debug}") typer.echo(f"Output Dir: {output_dir}") typer.echo(f"start flows: {flows}") @app.command() def stop( debug: bool = typer.Option(False), output_dir: str = typer.Option(os.getcwd())): typer.echo(f"Debug mode: {debug}") typer.echo(f"Output Dir: {output_dir}") typer.echo("STOP!") @app.command() def clean( debug: bool = typer.Option(False), output_dir: str = typer.Option(os.getcwd())): typer.echo(f"Debug mode: {debug}") typer.echo(f"Output Dir: {output_dir}") typer.echo("STOP!") if __name__ == "__main__": app()

The same way as with a CLI application with a single command, subcommands (or just "commands") can also have their own CLI arguments: ... import typer app = typer.Typer() @app.command() def create(username: str): print(f"Creating user: {username}") @app.command() def delete(username: str): print(f"Deleting user: {username}") if __name__ == "__main__": app() // Check the help for create $ uv run python main.py create --help Usage: main.py create [OPTIONS] {username} Arguments: username [required] Options: --help Show this message and exit.